Method of removing surface defects.



F. 11.,SPELLER.

METHOD OF REMOVING SURFACE DEFECTS.

APPLICATION FILED FEB. 13, 1909.

1,006,602. Patented 0012 11911.

UNITED STATES PATENT OFFICE.

FRANK N. SPELLEB, PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO THE NATIONAL TUBE COMPANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OF NEW JERSEY METHOD OF REMOVING SURFACE DEFECTS.

Patented Oct. 24, 1911.

To all whom it may concern:

Be it known that I, FRANK N. SPELLER, of Pittsburgh, Allegheny county, Pennsylvania, have invented a new and useful Method of Removing Surface Defects, of which the followin is a full, clear, and exa'ct description, re erenoe being had to the accompanying drawings, forming part of this specification, in which- Figures 1, 2 and 3 are front elevations, showing successive rolls arranged for carrying out my process; and Fig. 4 is an enlarged view showing the detail of the corrugated pass.

In certain lines of manufacture, particularly in the manufacture of seamless tubing, much loss and waste has resulted by reason ofsmall surface defects in the billets. In the cases of billets for piercing, these surface defects often take the form of a twisted or spiral defect on'the pierced billet. This twisting or overlapping of the surface defect in the act of piercing, is a necessary incident to the use of the Mannesman piercing mill, and will occur in the Stiefel piercing mill if the mandrel is carelessly or improperly set. These surface defects being drawn out and elongated will be intensified in the subsequent operations, and consequently, there is considerable loss in waste, especially in the cases of pierced billets which arerelatively expensive products.

My invention is designed to work out these surface defects and thereby reduce the lossin production from such billets or blooms. It relates especially to billets for piercing, although it may be employed upon billets or blooms for other purposes.

The invention consists in passing the billet or bloom through a pass or passes having closely arranged circumferential corrugations, which will give side-work to the metal, the bloom or billet thereafter being rolled in passes having smooth faces to crush down and flatten the corrugations formed on the metal and thus work out the surface defect or defects.

The invention also consists in carrying out this process in closed passes between the rolls and also in corrugatin the faces of the blank, then flattening 1t, then aga n corrugating it and then again fiattenmg 1t.

In the drawings, Fig. 1 shows a stand of roughing rolls for billets to be used for piercing or for other purposes, 1n which a bloom is first .fed through pass a between the middle and lower rolls. This pass is a corrugated pass, the grooves in the two rolls having clrcumferentlal grooves or corrugatlons as shown in Fig. 4. These may be formed by turning in a lathe or in any other desirable manner. The metal returns through the plain pass 6 between the upper and middle rolls and is then fed forward through the third pass 0, which is a corrugated pass, between the midle and lower rolls. The metal is then fed through the upper plain pass d, thence through the lower corrugated pass e, and thence through the upper plain pass f. It may then also be passed through the passes g and h. The number of passes which are'used in the roughing set may, of course, be varied in accordance with the article desired, the reductions made,etc. In some cases, it may be desirable to provide more than one smooth pass to act upon the metal between the corrugated passes. From the roughing set the blank passes through the oval pass 70 in the second set of rolls shown in Fig. 2, and is then taken to the finishing set of Fig. 3, in which it passes first through the oval pass Land then through the finishing pass m. The oval and finishing passes may be combined in one set of rolls, or either or both may be placed in roughing rolls. In

the case of pierced billets, this ordinarily gives a four-inch round. For other shapes or kinds of material, the several grooves would, of course, be changed in number and form, as desired, the essence of the invention being the use of the 'circumferentially corrugated passes to give side work to the metal and form corrugations which are flattened out in further rolling in plain grooves or passages,'thus removing the surface defects.

The advantages of my invention result from the removal ofthe surface defects which have heretofore appeared in the pierced billet or other product. These surface defects being accentuated in the further rolling have caused much material to be scrapped which was good material except for these surface defects resulting from fissures or seams in the blooms. The scrap loss is therefore greatly reduced or almost eliminated by th1s process, in so far as it is on account of surface defects. 7

Many variations within the scope of the appended claims may be made in the form and arrangement of the metal or metals, the passes, etc., without departing from my invention.

I claim:

1. In the elimination of surface defects from metal blooms, billets, slabs, etc., the method consisting in reducing the cross sectional area of the metalby rolling, forming longitudinal corrugations in the surface during the rolling operation and removing the corrugations by flattening the ridges in a later rolling operation; substantially as described.

2. In the elimination of surface defects from metal blooms, billets, slabs, etc., the

method consisting in reducing the cross sectional area of the metal by rolling, forming longitudinal corrugations or furrows in the surface during the rolling operation, then flattening the so formed ridges, again forming longitudinal corrugations or furrows by rolling by flattening the ridges in a further rolling operation; substantially as described.

3. In the elimination of surface defects from blanks for making pierced billets, the method consisting in rolling the metal in a plurality of reducing passes, corrugating the defective surface of the metal by forming closely arranged longitudinally extending ridges and furrows therein in some of said reducing passes and then removing the corrugations by flattening the ridges in other of the rolling passes, and thereby removing the defects; substantially as described.

4, In the rolling of metal, the method of removing surface defects consisting in reducing the cross sectional area of the metal by rolling, forming and then removing longitudinal corrugations in the defective surand then removing the corrugationsface during the rolling operation, and then" again forming and removing the corrugations in a subsequent rolling operation, the corrugations being removed at the completion of the rolling operation; substantially as described.

5. In the elimination of surface defects from metal blooms and billets, the method consisting in reducing the cross-sectional area of the metal by rolling, forming lon tudinal corrugations on the surface of t e metal during the rollin operation and then removing the corrugatlons in a later roll- .ing operation; substantially as described.

6. In the elimination of surface defects from metal blooms and billets, the method consisting in reducing the cross sectional area by rolling, forming longitudinal corrugations in the surface of the metal during the rolling operation, then flattening the so formed corrugations, again forming longitudinal corrugations on the surface of the" metal and finally removing the corrugations by flattening in a further rolling operation; substantially as described.

7. In the rolling of metal, the method of 'remo surface defects consisting in reduc' e cross sectional area of the metal by i dfijng, and alternately forming and removing longitudinal corrugations on the surface of the metal during the rolling operation, the corrugations being removed at the completion of the rolling operation; substantially as described.

In testimony whereof, I have hereunto set my hand.

- FRANK N. SPELLER.

.Witnesses:

VIRGINIA KIEIIL, H. M. Conwm. 

